In some parts of the world, life can be extremely hazardous for enviromental activists.
For this project, journalist Fred Pearce travels to the rainforests of Sumatra, in Malaysian Borneo, to hear why an activist was shot dead in a drive-by shooting, apparently for standing up for a forest community when a palm oil company wanted their land.
He also visits the Xolobeni people in South Africa, who lost one of their activists fighting a titanium mine, which has brought conflict to a once peaceful coastal region.
And he looks into the background of the well-publicized slaying of Honduran anti-dam campaigner Berta Cáceres, apparently at the hands of U.S.-trained special forces. It emerges that both before and since her killing, others have been killed and violently assaulted in a long-running and deadly conflict.